(1) Field of the Invention
The present invention relates to a liquid crystal element, and a manufacturing method and a driving method thereof
(2) Description of the Prior Arts
A liquid crystal element is widely utilized for such a monitor and a projection type display as a word processor and a computer, and a small-sized portable television, and such an element for controlling light as an optical switching element. A conception of a liquid crystal element includes a liquid crystal display device and an optical switching element. A liquid crystal display device is described as a liquid crystal element unless mentioned particularly in the specification.
A twisted nematic (ICN) liquid crystal and a vertically aligned (VA) liquid crystal are mentioned as a typical example of a liquid crystal used for a liquid crystal element.
A twisted nematic (TN) liquid crystal has a drawback of a low contrast because of an alignment directivity of a liquid crystal molecule near a reverse tilt domain and an interface. Moreover, in both a TN liquid crystal and a VA liquid crystal, light transmittance and reflectance vary greatly with an angle with a liquid crystal element because of the directivity of molecular array, and both liquid crystals have a characteristic of viewing angle whereby the coloring and the decrease of contrast are caused.
In order to correct the viewing angle, a retardation film and a scattering film are disposed on a surface of a liquid crystal element using a TN liquid crystal. Meanwhile, in recent years a method of dividing an alignment direction on a pixel into two or four parts is used for a VA liquid crystal in order to widen the viewing angle, however, the problem is that the utilization efficiency of light decreases and the response time of liquid crystal decreases, and additionally the process of dividing an alignment direction on a pixel and aligning a liquid crystal divisionally becomes complicated. It has been considered that a generally high contrast is obtained in a VA liquid crystal, however, a contrast on a supreme level can not obtained because of light leakage by a slight inclination of a liquid crystal molecule in a black display.
Thus, the problem is that conventional TN liquid crystal and VA liquid crystal have a great dependence on viewing angle, and the coloring, the decrease of contrast and tone reversal occurs according to a direction of viewing. Furthermore, the speed of response is unsatisfactory.
Recently, an in-plane switching (IPS) method, which is developed for improving a characteristic of viewing angle, is noticeable. Although the IPS has a superior characteristic of viewing angle because of driving a liquid crystal molecule on a substrate plane, an insulating layer on an electrode is necessary for preventing a short circuit between electrodes because of forming both electrodes on the same plane of the same substrate. The problem is that the IPS has an image persistence in displaying a fixed pattern for many hours because of the insulating layer.
A general liquid crystal element has a structure in which liquid crystal is sealed between two substrates. When an alignment direction of a liquid crystal molecule in liquid crystal becomes nonuniform in sealing liquid crystal between two substrates, irregularities occur in an alignment direction of a liquid crystal molecule of each pixel on an initial condition. Then, even if a voltage on the same condition is applied to each pixel, a disclination line appears nonuniformly at each pixel. When a display image is a black screen in using a liquid crystal element as a liquid crystal display device, an observer of the screen sees as if white sand would be scattered on the black screen and the screen were spotted.
In a homeotropic type liquid crystal display device (a liquid crystal element) wherein all liquid crystal molecules are aligned vertically to a substrate, a method of improving a display characteristic by providing an aperture for an opposite electrode and controlling electric field is disclosed in Japanese Unexamined Patent Publications No. 3-259121 and No. 6-301036.
The Publication No. 3-259121 relates to a dot matrix type liquid crystal display device, and as shown in FIG. 1, a slender aperture 51 is provided for a crossing portion of a first electrode (pixel electrode) 1 on the side of a TFT substrate and a second electrode (opposite electrode) 3 on the side of an opposite substrate, namely, the second electrode (opposite electrode) 3 in a display portion in a pixel.
Therefore, a diagonal electric field is caused in the crossing portion of the first electrode (pixel electrode) 1 and the second electrode (opposite electrode) 3, and as shown in FIG. 1(b), a liquid crystal molecule 7 is aligned uniformly in a predetermined direction by the diagonal electric field.
The Publication No. 6-301036 relates to an active matrix type liquid crystal display device, and an area, in which a liquid crystal molecule is not inclined remaining vertical, exists by providing an approximately square aperture for a central portion of an opposite electrode, which is opposite to a pixel electrode, namely, a display portion of a pixel, and forming an area with little or no electric field in the pixel electrode despite an existence (ON, OFF) of display. Therefore, the array of a liquid crystal molecule in other areas of the pixel is improved, a disclination line, which is a drawback resulting from the nonuniformity of array, is fixed, spots of the screen never occurs, the liquid crystal molecule is inclined in various directions (four directions) in a pixel, and thereby a characteristic of viewing angle is improved.
However, in either of these methods, since an aperture exists in an opposite electrode, opposite to a pixel electrode, namely, originally a display area, a discination line always occurs in such a boundary between areas wherein a liquid crystal molecule is inclined in a different direction, and an area wherein a liquid crystal molecule is not inclined despite an existence of electric field as a central portion and a corner of the aperture. FIG. 1(c) shows this state in a liquid crystal display device of the above-mentioned Publication No. 3-259121. As shown in FIG. 1(c), a disclination line 9 occurs at both ends of the aperture 51.
Consequently, a liquid crystal display device (a liquid crystal element) having an aperture causes a remarkable decrease in light transmittance, such as a black portion in a white display.
Since an aperture exists in an opposite electrode in a pixel, which is originally a display portion, the resistance of light transmission increases. In addition, since an aperture which does not conduct electricity exists in an opposite electrode, a voltage in an opposite electrode away from a connection terminal portion decreases greatly, whereby the unevenness of luminance on a display plane occurs.
Accordingly, it has been desirable to actualize a liquid crystal display device wherein, by means of not causing a discination line in a pixel display portion, a decrease in the utilization efficiency of light is never caused, the unevenness of luminance on a display plane never occurs, and the viewing angle toward up and down as well as right and left is improved.
The object of the present invention is to provide a liquid crystal element with a high contrast and a characteristic of a wide viewing angle, wherein a liquid crystal molecule responses at a high speed, and a manufacturing method thereof. The first group of inventions for achieving the object relates to a liquid crystal element characteristic of the motion of a liquid crystal molecule, and a manufacturing method and a driving method thereof. The second group of inventions for achieving the same object relates to a liquid crystal element characteristic of the shape of an opposite electrode.
A liquid crystal element in the first group of inventions is characterized of comprising a liquid crystal molecule which moves in two or more directions phasedly or gradually by applying voltage.
Since a liquid crystal molecule moves in two different directions, the transmittance and cutoff of incident light can be controlled, and the switching is executed on a plane in a liquid crystal element in the first group of inventions like IPS mode. Therefore, a characteristic of a wide viewing angle is obtained.
Another liquid crystal element in the first group of inventions is characterized of comprising a liquid crystal having a liquid crystal molecule, and two substrates holding the liquid crystal; and in that an information for aligning a liquid crystal molecule in two or more directions phasedly or gradually by applying voltage is provided for the above-mentioned two substrates.
Another liquid crystal element in the first group of inventions is characterized of comprising a liquid crystal having a liquid crystal molecule, and two substrates holding the liquid crystal; and in that an information for aligning a liquid crystal molecule in two or more directions phasedly or gradually by applying voltage is provided for only one of the above-mentioned two substrates.
A dielectric anisotropy of a liquid crystal used for the above-mentioned liquid crystal element can be made negative. It is preferable that, in a liquid crystal element having a liquid crystal with a negative dielectric anisotropy, the liquid crystal molecule contacts with a surface of either or both of the above-mentioned two substrates at an angle of 80 to 90xc2x0. That is, the utilization efficiency of light can be raised by a vertically aligned (VA) cell.
A dielectric anisotropy of a liquid crystal used for the above-mentioned liquid crystal element can be made positive. It is preferable that, in a liquid crystal element having a liquid crystal with a positive dielectric anisotropy, the liquid crystal molecule contacts with a surface of either or both of the above-mentioned two substrates at an angle of 0 to 10xc2x0. The utilization efficiency of light can be raised more by a horizontal alignment, in which the liquid crystal molecule contacts with a surface of both of the above-mentioned two substrates at an angle of 0 to 10xc2x0, than by a hybrid alignment.
As regards the above-mentioned information for aligning, whether a dielectric anisotropy of a liquid crystal is negative or positive, a first information for aligning is provided for only one of the substrates at an angle of approximately 0xc2x0 or 45xc2x0 with a transmission axis or an absorption axis of a polarizer, and additionally, a second information for aligning is provided for the same substrate at an angle of 45xc2x0 with the above-mentioned first information for aligning. According to these two information for aligning, a high contrast and a wide viewing angle are obtained by changing an alignment direction of a liquid crystal element under an application of voltage.
When the first and second information for aligning is provided not merely for only one of the substrates but also for the two substrates, a higher contrast and a wider viewing angle are obtained because of a stronger control of alignment. Then, it is desirable that a first information for aligning on a substrate is parallel or antiparallel with a first information for aligning on the other substrate, and a second information for aligning on a substrate is parallel or antiparallel with a second information for aligning on the other substrate.
For instance, in a VA liquid crystal mode wherein a liquid crystal molecule is aligned approximately vertically to both substrates, a liquid crystal molecule is aligned approximately vertically to both substrates under no application of voltage, and simultaneously is inclined a little in a direction of the first information for aligning. Then, it is desirable that a direction in which a liquid crystal molecule is inclined is a direction of a transmission axis or an absorption axis of a polarizer when a liquid crystal molecule is projected orthogonally onto a polarizer.
Next, a liquid crystal molecule is inclined further by applying voltage, and at some moment, the control of alignment of a liquid crystal molecule shifts from the first information for aligning to the second information for aligning gradually or phasedly, and a direction of an orthogonal projection of a liquid crystal molecule onto a polaiizer shifts gradually from the first information for aligning to the second information for aligning (a direction of an angle of approximately 45xc2x0 with the first information for aligning). Then, a direction of an orthogonal projection of a liquid crystal molecule onto a polarizer shifts from a direction of a transmission axis or an absorption axis of a polarizer to a direction of an angle of 45xc2x0 with a transmission axis or an absorption axis of a polarizer. Thus, a light, which is cut off and is not emitted by a polarizer under no application of voltage, is emitted under an application of voltage by disposing a polarizer on the outside (an incident light side and an emitted light side) of a substrate so that its transmission axis crosses each other at right angles.
Because of optical control wherein a liquid crystal molecule moves on a substrate plane, a characteristic of viewing angle is greatly superior to optical control wherein a liquid crystal molecule moves in a vertical direction to a substrate plane, such as an ordinary twisted nematic mode. Under no application of voltage (black display), since a direction of an orthogonal projection of a liquid crystal molecule onto a polarizer is a direction of a transmission axis or an absorption axis of a polarizer, a characteristic of contrast of a polarizer itself is obtained.
A liquid crystal used for a liquid crystal element in the present invention may have spontaneous polarization. A ferroelectric liquid crystal and an antiferroelectric liquid crystal are mentioned as a liquid crystal having spontaneous polarization.
It is preferable that the above-mentioned first and second information for aligning, which is provided for a substrate of a liquid crystal element in the present invention, is formed in a different method.
For instance, it is preferable that the above-mentioned first information for aligning is irregularities formed on a surface of one or both of the substrates. It is preferable that a shape (pitch, height and the like) of the irregularities on a substrate is different from the other substrate in the case of forming the above-mentioned first information for aligning on a surface of both of the substrates. The irregularities with arbitrary length, width and pitch may be arrayed in a direction or the irregularities with a uniform pitch may be formed in a stripe. It is preferable that the pitch is 2 xcexcm or less and a ratio of the height to the pitch is 0.01 to 10. A liquid crystal molecule for which an information for aligning is provided by such irregularities is easily aligned.
It is preferable that the above-mentioned second information for aligning is formed by rubbing, irradiation of ultraviolet rays and a slit for causing a lateral electric field which is provided for an electrode.
It is preferable to use a thin film transistor (TFT) and a metal-insulatormetal (MIM) as a driving element of a liquid crystal element in the first group of inventions.
It is possible to employ a stripe electrode for a simple matrix, a transparent electrode like ITO, and a reflective electrode composed of a substance with a high reflectivity like aluminum (Al) and silver (Ag) as an electrode of a liquid crystal element in the first group of inventions.
It is preferable that irregularities on a substrate of a liquid crystal element in the first group of inventions are composed of a flat electrode formed on a substrate, an insulating layer in a concavo-convex shape laminated on the above-mentioned electrode, a thin conductive layer laminated on the above-mentioned insulating layer, and a conductive continuity portion connecting the above-mentioned electrode and conductive layer.
The above-mentioned irregularities may have a microarea in a direction wherein a liquid crystal molecule is aligned. It is preferable that the microarea is aligned in two or more different directions and the directions cross each other at right angles. A viewing angle is improved further by aligning a liquid crystal molecule in two or more directions phasedly or gradually and aligning a liquid crystal molecule in different directions in each microarea.
A method of manufacturing a liquid crystal element in the first group of inventions is characterized of comprising a step of providing an information for aligning a liquid crystal molecule in a direction for a substrate with an electrode by applying voltage.
It is preferable that the above-mentioned step comprises a first step of providing an information for aligning a liquid crystal molecule in a direction for two substrates holding a liquid crystal having the liquid crystal molecule by applying voltage, and a second step of providing an information for aligning the liquid crystal molecule in a different direction from the above-mentioned direction phasedly or gradually for the above-mentioned substrates.
An information for aligning is provided for a substrate by providing irregularities on a surface of the substrate in at least one of the first step and the second step. A method of patterning with photosensitive resin is the easiest as a method of forming irregularities; either of the patterning with a photomask, the patterning with interferential fringes of laser, the patterning with a electron beam, and the patterning with a laser ablation may be used. Then, it is preferable that photosensitive resin is conductive. As another method of forming irregularities, the irregularities may be formed in a direction by coating an inorganic substance or an organic substance on a substrate; and adding a physical contact like extension, scratch and rub. Then, it is not necessary that the irregularities are arrayed regularly in a stripe. It is preferable that the coating of an inorganic substance or an organic substance is conductive.
As another method of forming irregularities, the irregularities may be added on a surface of a substrate by forming a pattern of irregularities on another substrate beforehand and transferring it. It is possible to transfer by rolling with a roll coater or to transfer by sticking with a flat plate. It is not necessary to transfer the whole substrate at a time, and the irregularities may be added on the whole substrate by dividing into small areas and transferring several times.
An information for aligning can be provided for a substrate by irradiating ultraviolet rays in at least one of the first step and the second step. Either of a linearly polarized light or not may be used as ultraviolet rays, and a linearly polarized light is preferable and additionally it is possible to irradiate at an angle with a substrate. If chemical bond reactive by ultraviolet rays exists on a surface of a substrate before irradiating, an information for aligning is provided easily because of the occurrence of bond and decomposition by irradiating ultraviolet rays. An alignment layer such as polyimide and siloxane available on public sale is used most easily.
A rubbing treatment can be executed on a substrate in at least one of the first step and the second step. Any cloth is used for rubbing, and rayon and cotton are general.
Another liquid crystal element in the first group of inventions is characterized of comprising at least one polarizer in addition to the above-mentioned liquid crystal element. Such polarizer is a film using resin like iodine and dyestuff, and a plate for polarizing light of Glan-Thomson prism utilizing crystal plane. It is possible to add a retardation plate and a scattering plate to the liquid crystal element and to widen a viewing angle.
Another liquid crystal element in the first group of inventions is characterized of comprising at least one polarized beam splitter in addition to the above-mentioned liquid crystal element. It is possible to add a retardation plate and a scattering plate to the liquid crystal element and to widen a viewing angle.
Furthermore, a liquid crystal element in the first group of inventions can be used as an optical switching element.
A method of driving a liquid crystal element in the first group of inventions is characterized of driving by applying a voltage above a higher appropriate voltage than a threshold voltage of a liquid crystal. A threshold voltage of a liquid crystal is a voltage at the moment when a liquid crystal moves by the voltage.
According to the first group of inventions, such an effect is obtained that a liquid crystal element with a high contrast, a wide viewing angle and a high-speed response can be provided by aligning a liquid crystal molecule in two or more directions phasedly under an application of voltage, and thereby all problems in conventional TN, VA and IPA modes can be solved.
The second group of inventions relates to a fullly devised opposite electrode. More specifically, the constitutions are described below.
A liquid crystal element in the first mode in the second group of inventions is characterized of comprising a multitude of pixel electrodes which are divided minutely, and a liquid crystal to which an electric field is applied by the above-mentioned pixel electrodes; and in that an electric field direction of the liquid crystal between at least one pair of adjacent pixels is inclined against an electrode plane.
A liquid crystal element in the second mode in the second group of inventions is characterized of comprising a multitude of pixel electrodes which are divided minutely, an opposite electrode which is disposed in parallel with the above-mentioned pixel electrodes, and a liquid crystal which is held between the above-mentioned pixel electrode and opposite electrode; and in that a nonconductive portion is provided in a part of the opposite electrode which is opposite to a gap between at least one pair of adjacent pixel electrodes.
A liquid crystal element, wherein a four-sided minute pixel electrode is arrayed in a lattice in X, Y directions crossing each other at right angles on a display plane, in the third mode in the second group of inventions is characterized of comprising, in view of Z direction at right angles with X, Y directions when a pixel of i-th position in X direction and j-th position in Y direction from an edge point or a standard point is defined as p (i, j), a first nonconductive portion, with a rectangular shape having a longer side in Y direction and a larger width in X direction than a distance between a pixel p (4m, 4n+1) and a pixel p (4m+1, 4n+1), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m, 4n) [m, n: an integer] and a pixel p (4m+1, 4n) as well as at least a part of a gap between a pixel p (4m, 4n+1) and a pixel p (4m+1, 4n+1); a second nonconductive portion, with a rectangular shape having a longer side in X direction and a larger width in Y direction than a distance between a pixel p (4m+1, 4n+2) and a pixel p (4m+1, 4n+3), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m, 4n+2) and a pixel p (4m, 4n+3) as well as at least a part of a gap between a pixel p (4m+1, 4n+2) and a pixel p (4m+1, 4n+3); a third nonconductive portion, with a rectangular shape having a longer side in X direction and a larger width in Y direction than a distance between a pixel p (4m+2, 4n) and a pixel p (4m+2, 4n+1), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m+2, 4n) and a pixel p (4m+2, 4n+1) as well as at least a part of a gap between a pixel p (4m+3, 4n) and a pixel p (4m+3, 4n+1); and a fourth nonconductive portion, with a rectangular shape having a longer side in Y direction and a larger width in X direction than a distance between a pixel p (4m+2, 4n+3) and a pixel p (4m+3, 4n+3), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m+2, 4n+2) and a pixel p (4m+3, 4n+2) as well as at least a part of a gap between a pixel p (4m+2, 4n+3) and a pixel p (4m+3, 4n+3).
Then, a minute pixel, which is employed on a display plane of a liquid crystal television set and a word processor, means that a person can not observe black and white (ON and OFF) of each liquid crystal element. The minute pixel is approximately 500 xcexcm (a large size) or less in a side, particularly 100 xcexcm or less, and desirably approximately 6 to 30 xcexcm.
According to the above-mentioned constitution, the following function is obtained in a liquid crystal display device wherein a pixel electrode and an opposite electrode are a four-sided figure suitable for disposition and manufacturing, and a minute pixel is arrayed in a lattice in X, Y directions crossing each other at right angles on a display plane.
In view of Z direction at right angles with X, Y directions when a pixel of i-th position in X direction and j-th position in Y direction from such an edge point or a standard point as the bottom and left in a pixel group is defined as p (i, j), a first nonconductive poison, with a rectangular shape (including a somewhat different case like four round comers due to manufacturing) having a longer side in Y direction and a larger width in X direction than a distance between a pixel p (4m, 4n+1) and a pixel p (4m+1, 4n+1), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m, 4n) [m, n: an integer] and a pixel p (4m+1, 4n) as well as at least a part of a gap between a pixel p (4m, 4n+1) and a pixel p (4m+1, 4n+1) is provided.
Likewise, a second nonconductive portion, with a rectangular shape having a longer side in X direction and a larger width in Y direction than a distance between a pixel p (4m+1, 4n+2) and a pixel p (4m+1, 4n+3), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m, 4n+2) and a pixel p (4m, 4n+3) as well as at least a part of a gap between a pixel p (4m+1, 4n+2) and a pixel p (4m+1, 4n+3) is provided.
Accordingly, in view of Z direction, an opposite electrode corresponding to a pixel electrode does not exist in a portion which includes each of at least a part of a gap as well as at least a part of the other gap.
Likewise, a third nonconductive portion, with a rectangular shape having a longer side in X direction and a larger width in Y direction than a distance between a pixel p (4m+2, 4n) and a pixel p (4m+2, 4n+1), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m+2, 4n) and a pixel p (4m+2, 4n+1) as well as at least a part of a gap between a pixel p (4m+3, 4n) and a pixel p (4m+3, 4n+1) is provided.
Likewise, a fourth nonconductive portion, with a rectangular shape having a longer side in Y direction and a larger width in X direction than a distance between a pixel p (4m+2, 4n+3) and a pixel p (4m+3, 4n+3), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m+2, 4n+2) and a pixel p (4m+3, 4n+2) as well as at least a part of a gap between a pixel p (4m+2, 4n+3) and a pixel p (4m+3, 4n+3) is provided.
Consequently, four nonconductive portions in total are provided on the side of the opposite electrode as a unit of 4xc3x974 pixels (in the case of black and white display). Each pixel is opposite to a nonconductive portion on only one side. Then, each nonconductive portion is arrayed vertically by turns in view of either of X, Y directions. In addition, a pair of adjacent pixels are opposite to a nonconductive portion.
Consequently, an alignment of a liquid crystal molecule is not irregular in a display area of a pixel, and the problem of an increase in a resistance of the opposite electrode never occurs.
As a result, a superior liquid crystal display device is obtained.
A liquid crystal element, wherein a four-sided minute pixel electrode is arrayed in a lattice in X, Y directions crossing each other at right angles on a display plane, in the fourth mode in the second group of inventions is characterized of comprising, in view of Z direction at right angles with X, Y directions when a pixel of i-th position in X direction and j-th position in Y direction from an edge point or a standard point is defined as p (i, j), a first nonconductive portion, with a rectangular shape having a longer side in Y direction and a larger width in X direction than a distance between a pixel p (4m, 4n+1) and a pixel p (4m+1, 4n+1), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m, 4n) [m, n: an integer] and a pixel p (4m+1, 4n) as well as at least a part of a gap between a pixel p (4m, 4n+1) and a pixel p (4m+1, 4n+1); a second nonconductive portion, with a rectangular shape having a longer side in X direction and a larger width in Y direction than a distance between a pixel p (4m+1, 4n+2) and a pixel p (4m+1, 4n+3), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m, 4n+2) and a pixel p (4m, 4n+3) as well as at least a part of a gap between a pixel p (4m+1, 4n+2) and a pixel p (4m+1, 4n+3); a third nonconductive portion, with a rectangular shape having a longer side in X direction and a larger width in Y direction than a distance between a pixel p (4m+3, 4n+3) and a pixel p (4m+3, 4n+4), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m+2, 4n+3) and a pixel p (4m+2, 4n+4) as well as at least a part of a gap between a pixel p (4m+3, 4n+3) and a pixel p (4m+3, 4n+4); and a fourth nonconductive portion, with a rectangular shape having a longer side in Y direction and a larger width in X direction than a distance between a pixel p (4m+2, 4n+2) and a pixel p (4m+3, 4n+2), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m+2 , 4n+1) and a pixel p (4m+3 , 4n+1) as well as at least a part of a gap between a pixel p (4m+2, 4n+2) and a pixel p (4m+3, 4n+2).
According to the above-mentioned constitution, the following function is obtained in a liquid crystal display device wherein a pixel electrode and an opposite electrode are a four-sided figure (including the case of several irregularities due to manufacturing), and a minute pixel is arrayed in a lattice in X, Y directions crossing each other at right angles on a display plane.
In view of Z direction at right angles with X, Y directions when a pixel of i-th position in X direction and j-th position in Y direction from an edge point or a standard point is defined as p (i, j), a first nonconductive portion, with a rectangular shape having a longer side in Y direction and a larger width in X direction than a distance between a pixel p (4m, 4n+1) and a pixel p (4m+1, 4n+1), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m, 4n) [m, n: an integer] and a pixel p (4m+1, 4n) as well as at least a part of a gap between a pixel p (4m, 4n+1) and a pixel p (4m+1, 4n+1) is provided.
Likewise, a second nonconductive portion, with a rectangular shape having a longer side in X direction and a larger width in Y direction than a distance between a pixel p (4m+1, 4n+2) and a pixel p (4m+1, 4n+3), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m, 4n+2) and a pixel p (4m, 4n+3) as well as at least a part of a gap between a pixel p (4m+1, 4n+2) and a pixel p (4m+1, 4n+3) is provided.
Likewise, a third nonconductive portion, with a rectangular shape having a longer side in X direction and a larger width in Y direction than a distance between a pixel p (4m+3, 4n+3) and a pixel p (4m+3, 4n+4), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m+2, 4n+3) and a pixel p (4m+2, 4n+4) as well as at least a part of a gap between a pixel p (4m+3, 4n+3) and a pixel p (4m+3, 4n+4) is provided.
Likewise, a fourth nonconductive portion, with a rectangular shape having a longer side in Y direction and a larger width in X direction than a distance between a pixel p (4m+2, 4n+2) and a pixel p (4m+3, 4n+2), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m+2, 4n+1) and a pixel p (4m+3, 4n+1) as well as at least a part of a gap between a pixel p (4m+2, 4n+2) and a pixel p (4m+3, 4n+2) is provided.
According to the above, the same function and effect as a liquid crystal element in the third mode in the second group of inventions is obtained as a whole and virtually aside from a side of top and bottom as well as right and left on a display plane in a liquid crystal element in the fourth mode in the second group of inventions.
A liquid crystal element, wherein a four-sided minute pixel electrode is arrayed in a lattice in X, Y directions crossing each other at right angles on a display plane, in the fifth mode in the second group of inventions is characterized of comprising, in view of Z direction at right angles with X, Y directions when a pixel of i-th position in X direction and j-th position in Y direction from an edge point or a standard point is defined as p (i, j), a first nonconductive portion, with a rectangular shape having a longer side in Y direction and a larger width in X direction than a distance between a pixel p (4m, 4n+1) and a pixel p (4m+1, 4n+1), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m, 4n) [m, n: an integer] and a pixel p (4m+1, 4n) as well as at least a part of a gap between a pixel p (4m, 4n+1) and a pixel p (4m+1, 4n+1); a second nonconductive portion, with a rectangular shape having a longer side in X direction and a larger width in Y direction than a distance between a pixel p (4m+1, 4n+2) and a pixel p (4m+1, 4n+3), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m, 4n+2) and a pixel p (4m, 4n+3) as well as at least a part of a gap between a pixel p (4m+1, 4n+2) and a pixel p (4m+1, 4n+3); a third nonconductive portion, with a rectangular shape having a longer side in X direction and a larger width in Y direction than a distance between a pixel p (4m+3, 4n+1) and a pixel p (4m+3, 4n+2), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m+2, 4n+1) and a pixel p (4m+2, 4n+2) as well as at least a part of a gap between a pixel p (4m+3, 4n+1) and a pixel p (4m+3, 4n+2); and a fourth nonconductive portion, with a rectangular shape having a longer side in Y direction and a larger width in X direction than a distance between a pixel p (4m+2, 4n) and a pixel p (4m+3, 4n), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m+2, 4nxe2x88x921) and a pixel p (4m+3, 4nxe2x88x921) as well as at least a part of a gap between a pixel p (4m+2, 4n) and a pixel p (4m+3, 4n).
According to the above-mentioned constitution, the following function is obtained in a liquid crystal display device wherein a pixel electrode and an opposite electrode are a four-sided figure, and a minute pixel is arrayed in a lattice in X, Y directions crossing each other at right angles on a display plane.
In view of Z direction at light angles with X, Y directions when a pixel of i-th position in X direction and j-th position in Y direction from an edge point or a standard point is defined as p (i, j), a first nonconductive portion, with a rectangular shape having a longer side in Y direction and a larger width in X direction than a distance between a pixel p (4m, 4n+1) and a pixel p (4m+1, 4n+1), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m, 4n) [m, n: an integer] and a pixel p (4m+1, 4n) as well as at least a part of a gap between a pixel p (4m, 4n+1) and a pixel p (4m+1, 4n+1) is provided.
Likewise, a second nonconductive portion, with a rectangular shape having a longer side in X direction and a larger width in Y direction than a distance between a pixel p (4m+1, 4n+2) and a pixel p (4m+1, 4n+3), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m, 4n+2) and a pixel p (4m, 4n+3) as well as at least a part of a gap between a pixel p (4m+1, 4n+2) and a pixel p (4m+1, 4n+3) is provided.
Likewise, a third nonconductive portion, with a rectangular shape having a longer side in X direction and a larger width in Y direction than a distance between a pixel p (4m+3, 4n+1) and a pixel p (4m+3, 4n+2), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m+2, 4n+1) and a pixel p (4m+2, 4n+2) as well as at least a part of a gap between a pixel p (4m+3, 4n+1) and a pixel p (4m+3, 4n+2) is provided.
Likewise, a fourth nonconductive portion, with a rectangular shape having a longer side in Y direction and a larger width in X direction than a distance between a pixel p (4m+2, 4n) and a pixel p (4m+3, 4n), which includes an opposite electrode corresponding to each of at least a part of a gap between a pixel p (4m+2, 4nxe2x88x921) and a pixel p (4m+3, 4nxe2x88x921) as well as at least a part of a gap between a pixel p (4m+2, 4n) and a pixel p (4m+3, 4n) is provided.
In the end, the virtually same function and effect as a liquid crystal element in the third and fourth modes in the second group of inventions is obtained in a liquid crystal element in the fifth mode in the second group of inventions.
A liquid crystal element in the sixth mode in the second group of inventions is characterized of being a liquid crystal element according to any one of the above-mentioned third to fifth modes; and in that the above-mentioned four-sided minute pixel electrode is rectangular in its plane shape, and an area in which each of first to fourth nonconductive portions with a rectangular shape, which include the above-mentioned opposite electrode, overlaps with the above-mentioned rectangular pixel electrode has a narrower width in a direction of a longer side of the pixel electrode than a width in a direction of a shorter side of the pixel electrode, in view of Z direction.
According to the above-mentioned constitution, the following function is obtained.
A plane shape of the pixel electrode is occasionally rectangular due to manufacturing and standard of a display plane. A direction of a longer side of the rectangular pixel electrode is different in a range affected by the nonconductive portion from a direction of a shorter side. A range of the influence of the nonconductive portion on molecular array can be equalized by narrowing a width in a direction of a longer side as compared with a width in a direction of a shorter side.
A liquid crystal element in the seventh mode in the second group of inventions is characterized of being a liquid crystal element according to any one of the above-mentioned third to fifth modes; and in that the above-mentioned four-sided minute pixel electrode is square in its plane shape.
According to the above-mentioned constitution, the following function is obtained.
The four-sided minute pixel electrode is square in its plane shape. Consequently, the pixel electrode is arrayed in a lattice on a display plane.
A liquid crystal element in the eighth mode in the second group of inventions is characterized of being a liquid crystal element according to any one of the above-mentioned third to seventh modes; and in that the above-mentioned four-sided minute pixel electrode is a pixel electrode for a color display wherein a pixel for three primary colors is arrayed in a mosaic.
These three primary colors are red, green and blue; or cyan, magenta and yellow.
According to the above-mentioned constitution, the following function is obtained.
An alignment does not exist in each color as a set of 96 pixels, and a fine image is obtained.
A liquid crystal element in the ninth mode in the second group of inventions is characterized of being a liquid crystal element according to any one of the above-mentioned sixth or seventh mode; and in that the above-mentioned four-sided minute pixel electrode is composed of three four-sided minor pixel electrodes for three primary colors, which are arrayed vertically to a direction of a longer side of the above-mentioned first to fourth nonconductive portions with a rectangular shape.
According to the above-mentioned constitution, the following function is obtained.
The crystal element is used for a color display, and thereby a four-sided minute pixel electrode is composed of three minor pixel electrodes for three primary colors, which are arrayed vertically to a direction of a longer side of an area, opposite to the corresponding pixel electrode, of first to fourth nonconductive portions with a rectangular shape.
A liquid crystal element in the tenth mode in the second group of inventions is characterized of being a liquid crystal element according to any one of the above-mentioned third to ninth modes; and in that the above-mentioned nonconductive portion with a rectangular shape is a nonconductive portion with a lap of 2 xcexcm wherein a width of its shorter side is larger by 4 xcexcm or more than a gap between two opposite pixels through its longer side.
According to the above-mentioned constitution, the following function is obtained.
The nonconductive portion with a rectangular shape is opposite with a width of at least 2 xcexcm to a pixel (electrode), in view of Z direction. Consequently, the array of molecule is affected greatly depending on a gap between substrates (electrodes) and the size of a pixel, and its forming is easy whether dry-etching or wet-etching.
A liquid crystal element in the eleventh mode in the second group of inventions is characterized of being a liquid crystal element according to any one of the above-mentioned third to tenth modes; and comprising a group of minor nonconductive portions which include an opposite electrode corresponding to at least a part of a gap between two opposite pixel electrodes or minor (sub) pixel electrodes through two longer sides of the nonconductive portion, instead of at least one (all in principle) of the above-mentioned first to fourth nonconductive portions.
According to the above-mentioned constitution, the following function is obtained.
Depending on the size of a display plane and a pixel, a group of minor nonconductive portions include an opposite electrode corresponding to at least a part of a gap between two opposite pixels or minor pixels through two longer side of the nonconductive portion, instead of at least one of the sizable first to fourth nonconductive portions.
Consequently, a decrease in voltage of the opposite electrode is reduced.
A liquid crystal element, wherein a four-sided minute pixel electrode is arrayed in a delta system for a color display on a display plane, in the twelfth mode in the second group of inventions is characterized of comprising, when a pixel row of i-th position from a bottom side upward is defined as q(i) and a group of three adjacent pixels of red, green and blue, which is composed of one of red, green and blue pixels in an odd pixel row q(2m+1) [m: an integer] and one of red, green and blue pixels in an even pixel row q(2m+2), is defined as a group of pixels for a color display and a group of pixels for a color display of j-th position from a left side on q(2m+1) and q(2m+2) is defined as Gqo), a first T-shaped nonconductive portion which includes an opposite electrode corresponding to each of at least a part of a gap between two adjacent pixels on q(2m+1) in a group of pixels for a color display composed of two pixels on q(2m+1) and a pixel on q(2m+2) as well as at least a part of a pixel on q(2m+2) facing the above-mentioned two pixels on q(2m+1); a first reverse T-shaped nonconductive portion adjacent to the above-mentioned first T-shaped nonconductive portion, which includes an opposite electrode corresponding to each of at least a part of a gap between two adjacent pixels on q(2m+2) in a group of pixels for a color display composed of a pixel on q(2m+1) and two pixels on q(2m+2) as well as at least a part of a pixel on q(2m+1) facing the above-mentioned two pixels on q(2m+2); a second T-shaped nonconductive portion shifted leftward by a pixel from the above-mentioned first T-shaped nonconductive portion, which includes an opposite electrode corresponding to each of at least a part of a gap between two adjacent pixels on q(2m+3) in a group of pixels for a color display composed of two pixels on q(2m+3) and a pixel on q(2m+4) as well as at least a part of a pixel on q(2m+4) facing the above-mentioned two pixels on q(2m+3); a second reverse T-shaped nonconductive portion adjacent to the above-mentioned second T-shaped nonconductive portion, which includes an opposite electrode corresponding to each of at least a part of a gap between two adjacent pixels on q(2m+4) in a group of pixels for a color display composed of a pixel on q(2m+3) and two pixels on q(2m+4) as well as at least a part of a pixel on q(2m+3) facing the above-mentioned two pixels on q(2m+4); a third T-shaped nonconductive portion shifted leftward by a pixel from the above-mentioned second T-shaped nonconductive portion, which includes an opposite electrode corresponding to each of at least a part of a gap between two adjacent pixels on q(2m+5) in a group of pixels for a color display composed of two pixels on q(2m+5) and a pixel on q(2m+6) as well as at least a part of a pixel on q(2m+6) facing the above-mentioned two pixels on q(2m+5); and a third reverse T-shaped nonconductive portion adjacent to the above-mentioned third T-shaped nonconductive portion, which includes an opposite electrode corresponding to each of at least a part of a gap between two adjacent pixels on q(2m+6) in a group of pixels for a color display composed of a pixel on q(2m+5) and two pixels on q(2m+6) as well as at least a part of a pixel on q(2m+5) facing the above-mentioned two pixels on q(2m+6).
According to the above-mentioned constitution, in a liquid crystal element (a liquid crystal display device) wherein a four-sided minute pixel electrode is arrayed in a delta system for a color display on a display plane, when a pixel row of i-th position from a bottom side upward is defined as q(i) and a group of three adjacent pixels of red, green and blue composed of one of red, green and blue pixels in an odd pixel row q(2m+1) [m: an integer] and one of red, green and blue pixels in an even pixel row q(2m+2) is defined as a group of pixels for a color display and a group of pixels for a color display of j-th position from a left side on q(2m+1) and q(2m+2) is defined as Gq(j), the following function is obtained.
A first T-shaped nonconductive portion which includes an opposite electrode corresponding to each of at least a part of a gap between two adjacent pixels on q(2m+1) in a group of pixels for a color display composed of two pixels on q(2m+1) and a pixel on q(2m+2) as well as at least a part of a pixel on q(2m+2) facing the above-mentioned two pixels on q(2m+1) is arrayed in a lateral (right and left) direction at every three pixels.
A first reverse T-shaped nonconductive portion adjacent to the above-mentioned first T-shaped nonconductive portion, which includes an opposite electrode corresponding to each of at least a part of a gap between two adjacent pixels on q(2m+2) in a group of pixels for a color display composed of a pixel on q(2m+1) and two pixels on q(2m+2) as well as at least a part of a pixel on q(2m+1) facing the above-mentioned two pixels on q(2m+2) is arrayed in a lateral (right and left) direction at every three pixels.
A second T-shaped nonconductive portion shifted leftward by a pixel from the above-mentioned first T-shaped nonconductive portion, which includes an opposite electrode corresponding to each of at least a part of a gap between two adjacent pixels on q(2m+3) in a group of pixels for a color display composed of two pixels on q(2m+3) and a pixel on q(2m+4) as well as at least a part of a pixel on q(2m+4) facing the above-mentioned two pixels on q(2m+3) is arrayed in a lateral (right and left) direction at every three pixels.
A second reverse T-shaped nonconductive portion adjacent to the above-mentioned second T-shaped nonconductive portion, which includes an opposite electrode corresponding to each of at least a part of a gap between two adjacent pixels on q(2m+4) in a group of pixels for a color display composed of a pixel on q(2m+3) and two pixels on q(2m+4) as well as at least a part of a pixel on q(2m+3) facing the above-mentioned two pixels on q(2m+4) is arrayed in a lateral (right and left) direction at every three pixels.
A third T-shaped nonconductive portion shifted leftward by a pixel from the above-mentioned second T-shaped nonconductive portion, which includes an opposite electrode corresponding to each of at least a part of. a gap between two adjacent pixels on q(2m+5) in a group of pixels for a color display composed of two pixels on q(2m+5) and a pixel on q(2m+6) as well as at least a part of a pixel on q(2m+6) facing the above-mentioned two pixels on q(2m+5) is arrayed in a lateral (right and left) direction at every three pixels.
A third reverse T-shaped nonconductive portion adjacent to the above-mentioned third T-shaped nonconductive portion, which includes an opposite electrode corresponding to each of at least a part of a gap between two adjacent pixels on q(2m+6) in a group of pixels for a color display composed of a pixel on q(2m+5) and two pixels on q(2m+6) as well as at least a part of a pixel on q(2m+5) facing the above-mentioned two pixels on q(2m+6) is arrayed in a lateral (right and left) direction at every three pixels.
A liquid crystal element in the thirteenth mode in the second group of inventions is characterized of being a liquid crystal element according to the above-mentioned twelfth mode; and comprising a longitudinal minor nonconductive portion forming a longitudinal area of the nonconductive portion between adjacent pixels in the same pixel row, a lateral minor nonconductive portion forming a lateral area between the above-mentioned adjacent pixels and a pixel in the same group of pixels for a color display as said adjacent pixels, which is opposite to both of these pixels, and a cutting portion of the nonconductive portion dividing the above-mentioned longitudinal minor nonconductive portion and the above-mentioned lateral minor nonconductive portion, instead of at least one of the above-mentioned first to third T-shaped and reverse T-shaped nonconductive portions.
According to the above-mentioned constitution, the following function is obtained.
A longitudinal minor nonconductive portion forming a longitudinal area of the nonconductive portion between adjacent pixels in the same pixel row, a lateral minor nonconductive portion forming a lateral area between the adjacent pixels and a pixel opposite to both of these pixels, and a cutting portion of the nonconductive portion dividing the longitudinal minor nonconductive portion and the lateral minor nonconductive portion, instead of at least one of the first to third T-shaped and reverse T-shaped nonconductive portions is provided in order to prevent a decrease in voltage to the utmost.
A liquid crystal element in the fourteenth mode in the second group of inventions is characterized of being a liquid crystal element according to any one of the above-mentioned twelfth or thirteenth mode; and in that the above-mentioned longitudinal minor nonconductive portion and lateral minor nonconductive portion instead of at least one of the above-mentioned first to third T-shaped and reverse T-shaped nonconductive portions is a nonconductive portion with a lap of 2 xcexcm having a common area with a width of at least 2 xcexcm, in view of Z direction at right angles with a display plane on which a pixel is arrayed.
According to the above-mentioned constitution, the following f-unction is obtained.
The above-mentioned longitudinal minor nonconductive portion and lateral minor nonconductive portion instead of at least one of the first to third T-shaped and reverse T-shaped nonconductive portions is a nonconductive portion with a lap of 2 xcexcm, and consequently the nonconductive portion has a common area with a width of at least 2 xcexcm, in view of Z direction at right angles with a display plane on which a pixel is arrayed. Thus, the same function and effect as a liquid crystal element in the ninth mode in the second group of inventions is obtained.
As described above, according to the second group of inventions, since a nonconductive portion never exists in an original display portion, such an effect is produced that it is possible to provide a liquid crystal display device having no disclination line and spots of a screen, and additionally a fine characteristic of viewing angle and a superior efficiency.